Introduction of fluids into a patient using a catheter and insertion device is known. For intravenous infusion, the most common insertion device is a syringe with a hollow needle received in a catheter. After insertion, some blood is extracted into the syringe before the syringe is removed from the catheter and a Luer coupler on the free end of the catheter connected to a fluid delivery system. These devices do not commonly have pre or post insertion needle covers or protectors. Another known system for intravenous infusion has a flexible catheter disposed within the bore of a hollow needle. After the needle is inserted into a vein, the catheter is pushed through the hollow end of the needle as the needle is retracted. A significant drawback of this type of device is that once the insertion needle is withdrawn, the needle cannot be removed from the catheter. The Luer lock or other coupling mechanism has a diameter too large to pass through the needle bore. Since the needle cannot be removed, it is continuously present on the catheter outside the patient's body and is a continuous source of possible problems.
A separable catheter insertion device is shown in U.S. Pat. No. 3,682,173. A longitudinal slot runs the length of the needle and of the hub member secured to the needle. The slot facilitates removal of the catheter from the needle after insertion of the catheter into the patient.
In a related application, now abandoned, filed Oct. 31, 1986, having Ser. No. 925,313 and assigned to the Assignee of the present application, a splittable needle functions to emplace a catheter. Once the catheter is in place, the applicator operates to slit the needle so that it can be removed from the catheter and disposed of.
The indicated devices with hollow needles allow for the extraction or flashback of blood when the vein has been pierced. In many cases such feature is important. There is another class of cases, however, where it is not necessary. Particularly, flashback does not occur when a catheter is inserted into a previously surgically emplanted port. A port is a device which forms a reservoir with a rubberized septum on the access side nearest the skin and a solid surface on a side opposite. The port further includes a tube leading from the reservoir to a vein or other blood vessel. The device is placed under the skin to provide a bacterial covering and is placed in a location convenient to the doctor considering the intended use. A port is commonly used to administer chemotherapy, is used to advantage in areas where the veins of the patient have collapsed or collapse easily, and may be used specifically to avoid flashback and provide safety to a clinician when treating a patient, for example, with AIDS.
The syringe type and other devices mentioned above which are known and used for intravenous access are not generally appropriate for accessing a port. The catheters do not have sufficient radical strength to avoid collapse at the septum and the internal diameter is small and limited by the size needle possible considering the use.
Generally, known devices for accessing ports are hollow needles (no catheters). The problem with hollow needles is the coring of the septum produced by the tip of the needle. Because of the causticity of medicines directed into a port and thereafter the venous system, it is important that medicines not leak from the port. Any coring of the septum reduces substantially the number of times which the septum can be accessed without unacceptably increasing the risk of leakage. Furthermore, the fact of coring limits the cross-sectional size of needles which can be introduced to a port.
Thus, to summarize, known catheter insertion devices enclose a relatively flexible catheter and are primarily intended for directly accessing a bio-target, commonly a vein. Generally, port access devices are hollow needles and do not emplace catheters. With the insertional devices enclosing catheters, the catheters are necessarily small and lack compressive strength. With the port access needles, coring can be a problem. The present invention uses a solid introducer and a catheter thereover so that it is particularly suited for accessing a port and removing and covering the introducer.